Research

Abstract: China’s sudden lifting of zero-COVID controls in December 2022 triggered a nationwide mortality surge. Using verifiable death records of social elites, such as academicians and key political figures, we estimate a conservative lower bound on excess mortality during the exit wave. We find that elite weekly mortality rates rose 5–10-fold in the weeks following the reopening, implying at least 1.44 million excess deaths nationally. Nevertheless, further analysis reveals that China’s total mortality cost during the entire pandemic remains low relative to comparable countries, as COVID-19 was largely under control from 2020 to 2022. The deaths of social elites highlight the pandemic’s reach across all societal strata and have far-reaching impacts on society. Using academia as an example, we demonstrate that while the deaths of academicians result in significant losses of valuable expertise, those deaths enhance academic upward mobility and accelerate generational turnover. Our findings underscore the need for better preparedness in future public health emergencies.

Old name: “Entry Regulation in the Presence of Reputation: Theory and Evidence”

Abstract: Ensuring reliable provision of high-quality goods and services remains a central challenge in many markets. This paper studies how reputation interacts with entry regulation and shapes optimal regulatory policies using empirical, theoretical, and quantitative approaches. Empirically, I show that an entry deregulation reform in the Environmental Impact Assessment (EIA) industry leads to a persistent decline in service quality. I also document that negative reputation shocks sharply reduce firms' market share by half, indicating that both regulation and reputation are powerful devices. Theoretically, I develop a firm entry game in which reputation partially substitutes for regulatory screening, weakening the quality-improving effect of entry barriers. Structurally, I estimate a dynamic oligopoly model within a Moment-based Markov Equilibrium framework that incorporates endogenous reputation formation. Counterfactual simulations reveal that accounting for reputation substantially alters the optimal stringency and timing of entry regulations. These results underscore that effective regulation in emerging markets must be designed jointly with the market’s reputation forces.

Abstract: This paper provides evidence that bribery demand plays a significant role in art valua-tion and art market dynamics. Specifically, we examine the phenomenon of “elegant corruption,” characterized by bribes concealed through the exchange of artwork gifts. Analyzing calligraphic artwork auction data in China, we find that promotions within the Chinese Calligraphers Association could significantly increase the trading value, volume, and prices of artworks. Anti-corruption measures targeting “elegant corruption” caused a market collapse for the prestigious artists’ works, indicating bribery’s important role in high-value art demand. Post-policy, artists shift efforts from political activities to marketing and research.

Abstract: This paper examines the effects of entry deregulation in the information intermediary sector, with a focus on China’s Environmental Impact Assessment (EIA) industry. We explore the implications of a market-oriented reform that eliminated entry barriers to the sector and analyze its impacts on EIA report quality, polluting firms, and local residents. Our findings reveal that, although the reform led to a five-fold increase in the number of EIA agencies, it inadvertently resulted in a decline in ser-vice quality. Consequently, firms became more likely to bypass EIA procedures for new projects, ultimately leading to a deterioration in ambient environmental condi-tions, which negatively affected the local population.

Abstract: Can governments improve governance durably without expanding enforcement capacity? This paper shows that time-limited campaign-style enforcement can generate persistent gains by ac-tivating citizen participation. Using China’s Central Environmental Inspection with a dynamic panel estimator and a difference-in-differences strategy, I find the campaign improves air quality by 4–9% in the long run, concentrated in SO₂ and PM2.5, and increases complaints by about 40%. Effects are amplified where NGO capacity is stronger. A theoretical framework explains persistence through citizens’ belief updating about government responsiveness. The findings suggest campaigns offer a cost-effective path to durable governance improvements in capacity-constrained settings.

Abstract: Nudge interventions, changes to choice architecture that preserve freedom of choice, have become prominent tools for promoting pro-environmental behaviors. This review synthesizes theoretical foundations and empirical evidence on five categories of environmental nudges: defaults, social nudges, information nudges, commitment devices, and framing and nonconscious nudges. For each, we discuss empirical patterns, behavioral mechanisms, and welfare implications. Three cross-cutting findings emerge: energy conservation and natural field experiments dominate; treatment effect heterogeneity across populations and countries is pervasive and increasingly emphasized; and cost-benefit and welfare analyses remain in short supply.

Abstract: Under what conditions do AI firms vertically integrate into downstream industries, and how should antitrust policy respond? I address these questions by developing a Nash-in-Nash bargaining model in which AI firms and downstream producers negotiate contracts. I characterize how R&D cost structures, AI-production complementarities, and market structure jointly determine integration incentives and welfare. The calibrated model yields three main findings. First, under current market conditions, vertical integration enhances welfare. Second, the welfare-reducing “cyberpunk” scenario emerges under technological democratization rather than monopolization. Third, I propose an Antitrust Alert Index that flags market conditions where vertical mergers warrant enhanced scrutiny.